Background & objectives: Sodium dithionite is used to improve the appearance of sugar products such as Shakar-Panir and rock candy. Use of this product at higher levels than the standard values will have dangerous side effects. The aim of this study was to determine residues of sulfur anhydride as an indicator of the presence of Blankit in sugarloaf, Shakar-Panir and rock candy in Ardabil province and comparing with the maximum allowable limits.

Methods: In this cross-sectional study, 88 samples of sugar products (48 sugarloaf, 11 Shakar-Panir and 29 rock candy) from Ardbil province markets were collected to determine sulfur anhydride residue as an indicator of the presence of Blankit in sugar products. The blankit residues of samples were measured using iodometry method and compared with the licensed 10 ppm by Institute of Standards & Industrial Research of Iran. Data were analyzed by descriptive statistics and ANOVA.

Results: The results showed that the Blankit levels in one-third of sugar products are higher than the maximum allowable levels of 10 ppm in Iran (33.3% of sugarloaf and 36.3% of Shakar-Panir). Blankit levels in all rock candy samples were less than the standard value of 10 ppm. Blankit in sugarloaf was significantly higher than Shakar-Panir and rock candy in Ardabil province, however, Blankit in Shakar-Panir samples was higher than rock candy and sugarloaf distributed in Ardabil city (p=0.013).

Conclusion: The results indicated that blankit levels in traditional rock candy are less than Shakar-Panir and sugarloaf as well as the national standard of Iran. One can say that in terms of Blankit level rock candy is suitable for consumption in comparison to other sugar products.